The present invention is related to a matrix and a method for purifying and/or isolating nucleic acids.
The purification and isolation of nucleic acids from biological samples is a key technology in molecular diagnostics, epidemiology, food analytics, forensics and biological science. One of the most popular approaches involves binding of nucleic acids to silica surfaces in the presence of chaotropic agents. The principles of this approach are for example described by Boom et al (1990), J. Clin. Microbiol. 1990 March; 28(3): 495-503. Kits utilizing this technology are for example marketed by BioMerieux, Qiagen or Promega.
Nucleic acids dissolved in a liquid sample have the ability to bind silica, i.e., amorphous SiO2, in the presence of high concentrations of chaotropic salts (“binding buffer”). The latter denature biomolecules by disrupting the hydration shell surrounding them. This allows positively charged (e.g., sodium ions provided with the binding buffer) ions to form a salt bridge between the negatively charged silica and the negatively charged DNA backbone. In a next step, a low ionic strength buffer (“low salt buffer”) is being used to disrupt theses bindings by solubilizing the nucleic acids, in order to elute the nucleic acids.